This competitive renewal application for a postdoctoral training program in pulmonary host defenses to microbial pathogens (HL-07889) at Case Western Reserve University (CWRU) seeks renewal funding for a research training program for M.D.,M.D.-Ph.D. and Ph.D. scientists. Funding for this novel training program was awarded in7/1998 on the strength of there search programs at CWRU in programmatic are as of tuberculosis, HIV and complications of cystic fibrosis. Research in pulmonary host defenses at CWRU has remained an institutional strength, with internationally recognized faculty with research programs on major pulmonary pathogens such as M. tuberculosis, HIV-1, Streptococcus pneumonia and Pseudomonas aeruginosa. Interdisciplinary approaches to study of host defenses to these bacterial and viral pulmonary pathogens involve faculty across basic and clinical departments and include immunology, molecular biology, biochemistry, genetics and cell biology. The interdisciplinary collaborations at CWRU in the area of pulmonary host defenses against microbial pathogens are greatly facilitated by the infrastructures of the Tuberculosis Research Unit (TBRU), the Center for AIDS Research (CFAR), the AIDS Clinical Trails Unit (ACTU), the Cystic Fibrosis Center and the NIH-funded Clinical Research Center (GCRC). In addition, strong basic research programs in the Departments of Pediatrics and Medicine in close proximity to and collaboration with clinical scientists has created a rich environment allowing trainees to learn how basic research translates into clinical investigation. The goals of the research training program are: 1. To provide rigorous training for promising M.D., M.D.-Ph.D. and Ph.D. postdoctoral fellows in the application of the tools of immunology, molecular biology or biochemistry to pulmonary host defenses to pathogens such as M. tuberculosis and HIV-I. 2. To assume an active role in career development by training and assisting trainees in securing funding either for additional postdoctoral training or for faculty development depending on their level of training at entree into the program and development in the training program.